How I use the value selected from drop down list from one file into the another file in flutter

user_15552025 0
Viewed 889

I am working with flutter. I create a DropDown menu in the menu_list.dart file. I want to use the value selected from the user in (menu_list.dart file) in the add_screen.dart file. So, that I can upload it in the FireStore with other user information. The code is attached below. I am glad if someone helps.

    'add_Screen.dart'
    import 'package:cloud_firestore/cloud_firestore.dart';
    import 'package:database/widgets/menu_list.dart';
    import 'package:flutter/material.dart';
    
    class AddScreen extends StatelessWidget {
      String? personname, personphone, vall;
    
      @override
      Widget build(BuildContext context) {
        return Scaffold(
          appBar: AppBar(
            title: Text("Add Data"),
          ),
          body: Column(
            children: [
              Container(
                child: MenuList(),
              ),
              SizedBox(
                height: 15,
              ),
              Container(
                child: TextFormField(
                  onChanged: (String name) {
                    getStudentName(name);
                  },
                  decoration: InputDecoration(
                    labelText: "Name",
                    focusedBorder: OutlineInputBorder(),
                  ),
                ),
              ),
              SizedBox(
                height: 15,
              ),
              Container(
                child: TextFormField(
                  onChanged: (String phone) {
                    getStudentPhone(phone);
                  },
                  decoration: InputDecoration(
                    labelText: "PhoneNumber",
                    focusedBorder: OutlineInputBorder(),
                  ),
                ),
              ),
              SizedBox(
                height: 15,
              ),
              Container(
                child: RaisedButton(
                  child: Text("Add"),
                  onPressed: createData,
                ),
              ),
            ],
          ),
        );
      }
    
      createData() {
        Future<void> documentReference = FirebaseFirestore.instance
            .collection("Students")
            .doc("subcollection")
            .collection("collectionPath")
            .doc()
            .set(
          {
            "PersonName": personname,
            "PersonPhone": personphone,
          },
        );
      }
    
      getStudentName(name) {
        this.personname = name;
      }
    
      getStudentPhone(phone) {
        this.personphone = phone;
      }
    }
    `
    ----------------------------------------------------------------------------------------------
    'menu_list.dart'

    `
    import 'package:flutter/material.dart';
    
    class MenuList extends StatefulWidget {
      const MenuList({Key? key}) : super(key: key);
      @override
      _MenuListState createState() => _MenuListState();
    }
    
    class _MenuListState extends State<MenuList> {
      final items = ['Maths', 'Urdu', 'English', 'Simple'];
    
      String? value;
    
      @override
      Widget build(BuildContext context) {
        return DropdownButton<String>(
          value: value,
          isExpanded: true,
          items: items.map(buildMenuItem).toList(),
          onChanged: (value) => setState(
            () => this.value = value,
          ),
        );
      }
    }
    
    DropdownMenuItem<String> buildMenuItem(String item) => DropdownMenuItem(
          value: item,
          child: Text(
            item,
            style: TextStyle(
              fontWeight: FontWeight.bold,
              fontSize: 30,
            ),
          ),
        );
    `
google-cloud-firestore firebase flutter android
2 Answers

I think the best option for you, without overegineering the code, would be to pass a callback function that is received as parameter for the onChanged parameter of the DropdownButton.

It would look something like this:

In add_screen:

String _itemSelected;
MenuList(onChanged: (value) {
    _itemSelected = value;
})

In menu_list:

class MenuList extends StatefulWidget {
    final Function(String) onChanged;
    const MenuList({required this.onChanged, Key? key}) : super(key: key);
    @override
    _MenuListState createState() => _MenuListState();
}

class _MenuListState extends State<MenuList> {
    final items = ['Maths', 'Urdu', 'English', 'Simple'];

    String? value;

    @override
    Widget build(BuildContext context) {
        return DropdownButton<String>(
            value: value,
            isExpanded: true,
            items: items.map(buildMenuItem).toList(),
            onChanged: widget.onChanged
        );
    }
}

I apologize if the code doesn't compile directly since I'm not able to compile it at the time.

Feel free to reach me if you have any questions

user_109766680 
class AddScreen extends StatefulWidget {
  @override
  _AddScreenState createState() => _AddScreenState();
}
class _AddScreenState extends State<AddScreen> {
  // make stateful
  String? personname, personphone, vall, dropdownValue;
  // define value for dropdownValue

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Add Data"),
      ),
      body: Column(
        children: [
          Container(
            child: MenuList(dropdownValue: dropdownValue),
            // call MenuList as above passing dropdown value;
          ),
          ...
          // other children
        ],
      ),
    );
  }
}


// menu_list.dart
import 'package:flutter/material.dart';

class MenuList extends StatefulWidget {
  String dropdownValue;
  // pass the value here
  MenuList({Key? key, this.dropdownValue}) : super(key: key);
  @override
  _MenuListState createState() => _MenuListState();
}

class _MenuListState extends State<MenuList> {
  final items = ['Maths', 'Urdu', 'English', 'Simple'];
  // String? value;

  @override
  Widget build(BuildContext context) {
    return DropdownButton<String>(
      value: widget.dropdownValue,
      // set the value here
      isExpanded: true,
      items: items.map(buildMenuItem).toList(),
      onChanged: (value) => setState(
        () => widget.dropdownValue = value,
        // set the value here
      ),
    );
  }
}
user_101360130
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